1. Field of the Invention
This invention relates generally to internal combustion engines, and pertains more particularly to a mechanism utilizing a single rocker arm for variably controlling the operation of one or more of an internal combustion engine's valves.
2. Description of the Prior Art
Various mechanisms have been devised for controlling the opening and closing of the inlet and exhaust valves associated with internal combustion engines. An example of one such prior art mechanism is the mechanism disclosed in U.S. Pat. No. 2,934,052, granted on Apr. 26, 1960 to Irvin R. Longenecker for "VALVE OPERATING MECHANISM." While other prior art mechanisms possess various shortcomings, such as being capable of controlling only valve lift or valve duration, but not both, the mechanism described in the referred to Longenecker patent results in more friction than is desirable and concomitantly produces excessive lateral thrust on the valve stem that is also objectionable. In addition, other mechanisms have been quite massive, involving a considerable amount of inertia, and requiring more space than is sometimes available, particularly when installed on the engines of compact and subcompact vehicles. Still others are quite complicated and costly to manufacture, thereby discouraging their adoption.